Casing for integrated operating air supply and air signal transmission service center



June 9, 1964 N. L. MAssEY 3,136,442

CASING FOR INTEGRATED OPERATING AIR SUPPLY AND AIR SIGNAL TRANSMISSIONSERVICE CENTER Original Filed April 22, 1959 2 Sheets-Sheet 1 NORMAN lMASSEY ATTOR N EYS `lune 9, 1964 N. L.. MASSEY 3,136,442

CASING FOR INTEGRATED OPERATING AIR SUPPLY AND AIR l SIGNAL TRANSMISSIONSERVICE CENTER Original Filed April 22, 1959 2 Sheets-Sheet 2 INVENTOR.

NO R MAN L. MASSEY ATTORNEYS United States Patent O CASING FORINTEGRATED OPERATING AIR SUP- PLY AND AIR SIGNAL TRANSMISSION SERVICECENTER Norman L. Massey, Middleboro, Mass., assignor to The BadgerCompany, Inc., a corporation of Massachusetts Original application Apr.22, 1959, Ser. No. 808,254, now Patent No. 2,994,339, dated Aug. 1,1961. Divided and this application Mar. 20, 1961, Ser. No. 97,102

2 Claims. (Ci. Htl- 3.8)

This invention relates to the distribution of operating air as well asair signals in a pneumatic system for instruments and control equipment.This application is a division of application Serial No. 808,254 iiledApril 22, 1959, which has since matured into Patent No. 2,994,339,issued August 1, 1961.

In chemical and petroleum processing plants, uid process controlequipment, such as valves, are often pneumatically operated, with thecontrol equipment being actuated by means responsive to pneumaticsignals from transducers or the like operatively associated withinstruments for measuring variables such as temperature, ow rate, etc.The air supply requirement for the operation of the control equipmentand for providing air to the transducers is usualy met by providing acentral air supply having a main supply pipe or conduit and branch pipelines from the main pipe to suppiy air at a pressure of 30 to 100p.s.i.g. at the location of each such instrument. It is normal toprovide at and for each such instrument a shut-off valve and an airsetto provide clean, dry air to the instrument at a reduced constantpressure of perhaps 20 p.s.i.g. For the purposes of this discussion aswell as the following description and claims, an airset is deiined aseither a unitary device or a combination of devices for connection to anair supply line and having means such as a pressure regulating valve toprovide a constant pressure output, means to filter the output air, andmeans such as a drip well to assure that the output air from the airsetis suicienly dry. The transmission of pneumatic signals from thetransducers and to the actuating means for the control equipment isusually handled by multiple run tubing of a size suicient to transmitthe relatively low pressure signals (3 to 15 p.s.i.g.). The multiple runtubing conducts these signals from the transducers to a central controlboard, which may be provided with indicating equipment as well as withmeans for determining the operation of the control equipment in responseto variations in the pneumatic signals. Thus, a network of air supplylines is utilized to supply operating air to individual airsets at eachpiece of control equipment, while a separate multiple run tubing systemis utilized for pneumatic signal transmission between the measuring andcontrol instruments and the control board. Such an arrangement, of'course, requires many separate airsets as well'as a rather complexarrangement of conduits and lines, which results in the expenditure ofconsiderable time and expense when a change in location of the controlequipment is desired or necessary, particularly with respect to the highpressure lines to the airsets.

It is an object of this invention to provide` a casing k,

for a service center of the type described having a novel and improvedconstruction whereby no latches or the like are required to maintain thecasing closed while at the same time the casing provides superiorprotection of equipment located therein against weather damage when theservice center is disposed in an exposed location.

The manner in which the foregoing and other objects of the invention areachieved in a preferred embodiment of the invention will be apparentfrom a consideration of the following description thereof taken inconnection ICC with the accompanying drawings illustrating the same andin which:

FIG. 1 is a front view of a service center constructed in accordancewith the invention and with the cover or door removed;

FIG. 2 is an enlarged cross section substantially along the line 2-2 ofFIG. l;4

FIG. 3 is a reduced perspective view of the service center of FIG. 1with the cover in place and closed;

FIG. 4 is a perspective view of the casing of the service center of FIG.3 with the cover open; and

FIG. 5 is an enlarged fragmentary view of a portion of the casing ofFIG. 4.

With reference to the drawings and particularly FIG. l, a preferredembodiment of a service center constructed in accordance with theinvention is shown as comprising a casing 10 having a tlat rectangularrear wall 12, a rectangular top wall 14, and a rectangular bottom wall16. The top wall is provided with a central opening for the reception ofa multiple run tubing or conduit 18 which, as best shown in FIG. 2,comprises a central relatively large diameter tube 20 for carrying highpressure air from a central supply and a plurality of circularlyarranged smaller tubes 22 disposed concentrically about the central tube20 for carrying relatively low pressure air signals. The tubes 20 and 22are maintained in assembly and protected by a sheath 24 of suitablematerial, such as plastic or metal. As apparent from FIG. 1, after theconduit 18 has been fed through the top of the casing, the sheath 24 isremoved from a portion of the end of the conduit disposed within thecasing and the separate air signal transmission tubes 22 arerespectively connected to the lower ends of a plurality of bulkheadcouplings 26 on the top wall 14 of the casing. The upper ends of theconnectors or couplings 26 may be connected 'to air signal tubing fromindividual instruments in the immediate vicinity. In order to preventdirt or other foreign matter from entering the coupling 26, suitableclosures may be provided, if desired.

The central high pressure air tubing 20 of the conduit 18 is connectedto a manually operable valve 28 mounted on a bracket 30 on the rear wallof the casing. The valve is provided with an operating handle 31 andwith a pair of outlets connected respectively to a pair of airsets 32,with the coupling or tubing which connects the valve and airsets alsosupporting the airsets within the casing. The valve 28 is preferably ofa four-position type constructedv to permit selective connection of thetube 20 to either or both of the airsets or the disconnection of bothairsets from the tube 20. The airsets 32 each generally comprise a ilterportion 34, a pressure regulating portion 36 having a pressure gauge 38,and a drip well portion 40. Each drip well portion is provided with adrain in the bottom thereof, with a valve 42 connected to the drainV andtoa drain tube 44 for the removal of water collected in the drip well.

Each airset has an outlet connected by an elbow 46 to tubing 48, inturnconnected to a valve 50 at the bottom of the casing. The valve 50 isconnected to a manifold 52 mounted on the underside of the bottom wall16 of the casing, with themanifold being provided at its underside witha plurality of additional valves 54 adapted to be connected to airoperated control equipment or transducers for the supply of operatingair thereto. If desired, as shown in FIG. 1, a connector 51 may beinstalled between the valve 28 and central air supply line 20 to providefor the connection of lines 53 between the supply line 20 and aplurality of connectors 55 mounted on the top Wall 14 of the casing asshown in FIG. 3. In this manner, a supply of airV at central air linepressure is also available at the service center, if needed. It shouldbe here noted that it is prefcrred that the connectors 55 besubstantially larger than the connectors Z6 so as to preclude theinadvertent connection of an air signal line to one of the high pressureconnectors 55.

As is best shown in FIGS. 3 to 5 of the drawings, the top wall 14 of thecasing is provided with a depending lip or flange 56 along its side andfront edges and merging at its rearward ends to form an extension of aside flange or lip 58 on the rear wall 12 extending at right angles andforwardly thereof. The bottomy wall 16 is provided Y with an upstandingflange 60 along its side and front edges, with the side portions of theflange 60 being spaced inwardly from and between the flanges 58 on therear wall, as bestfshown in FIG. l.

The casing also includes a cover 62 comprising a flat rectangular coverplate 64 forming the front wall of the casing. Integral side walls 66extend at right angles and rearwardly from the side edges of the coverplate 64 to provide a U-shaped configuration to the cover. The flat,generally rectangular side walls 66 are pivotally mounted on the sideportions of the flange 60 on the bottom wall by means of pins 68 on theflange which are slidably received in J-shaped slotsr7ll in the sidewalls 66, all as most clearly shown in FIG. 5. l

The spacing of the forward walls of the cover is selected to be suchthat the 'rear edge portionsl of the sidewalls 66 are receivable betweenthe side flanges 58 on the rear wall and the side portions of the flange60 ony the bottom wall when the cover is in its closed position.Further, the cover plate 64 and side walls 66 are longitudinally andlaterally dimensioned so that when the cover is in the closed positionof FIG. 3 the top edge portions of the cover plate and side walls willproject upwardly behind or, in other words, be telescopically receivedwithin the depending flange 56 on the top wall 14, and the bottom edgeportions of the cover of the plate will overlie at least a part of thefront portion of the flange 60 on the bottom Wall.

Y To close the cover from its openr position, shown in FIG. 4, whereinthe pins 68 are located in the short leg 76 of the slot 70, the cover isswung upwardly to a near vertical position and then moved downwardlyuntil the pins 63 engage the terminal end of the long legs of the slots.In this position of the cover plate, the top edge portion thereof willbe lower than the bottom edge of the depending ange 56 on the top wallof the casing. Thereupon, the cover plate is swung in and lifted untilthe pins bottom in the bight portion 74 joining the longer leg 72 of theslots 36 with the shorter leg 76, while at the same time slipping thetop edges of the cover within the flange 56 on the top wall andsimultaneously moving the bottom of the cover inwardly of the casingtoward the rear wall. The cover may then be lowered to engage the pinswith the terminal ends of the short legs of the slots, wherebyy thecover will be supported in the closed position shown in FIG. 3. Itshould here be noted that, as shown in FIGS. 3 and 4, it is preferredthat the top edges Vof the side walls 66 be inclined rearwardly anddownwardly to facilitate opening and closing of theV cover. y

When the'cover is in its closed position, shown in FIG. 3, with the topportions ofthe cover plate and side walls received within the flange 56,and with the rear edges of the side walls received between and behindthe side flanges 5S on the rear wall, it can be seen that eX- cellentprotection is afforded against the entrance of rain or other foreignmatter into the casing. Further, as can be easily seen, no separatelatch or lock is required to hold the cover closed in order to assuresatisfactory protection of the contents of the casing from weatherdamage.

In the use of a service center constructed in accordance with thisinvention, the service center is disposed in a location nearby theinstruments and control equipment which it is desired to service. Foreach instrument transmitter or transducer, two lines would be run to theservice center, one for'connection to a valve 54 for air supply to theinstrument, and the other for connection to a bulkhead coupling 26 forsignal transmission to a central control through'the conduit 1S.Similarly, for each control or control valve either a supply line to avalve 54 or a control signal line from a coupling 26 or both would beprovided. The airsets 32 in the service center provide clean, constantpressure air for the instruments serviced by the center, thuseliminating individual airsets for each airv operated piece of equipmentand materially reducing the total number of airsets required. The dripwells in each of the airsets provide low-point drains for the operatingair distribution system, replacing the drip legs normally installed inoperating air supply mains. The provision of the pair of airsets withinthe service center, along with the dual Valving therefor, permits bothairsets to be usedl in parallel during normal operation. In such use,one of the airsets is able to maintain desired air pressure While theother merely idles. If malfunction occurs in one ofthe airsets, theother will compensate for failure or erratic behavior of the first; andeven with one airset fouled, complete failure will not occur. When amalfunctioning has been detected in either airset, it may be easilyremoved and repaired or replaced without interruption o-f service to theinstruments by reason of the-valve 28 being operative to connect eitherof the airsets, solely, to the central air supply. Normally, thebulkhead signal line connectors on the service center will be the onlyjoints in the transmission lines between the control board and theprocess area measurement and control devices, which, of course,simplifies the-checking of leaks after installation, as well as reducingthe possibility of such leakage.

Thus, a service center constructed in accordance with this inventioneliminates the separate operating air and air signal network previouslynecessary and permits new instruments to be added to the system withoutinterruption of service to the ones already operating. The use of such aservice center further reduces the material cost of the installation ascompared to old unintegrated systems as well as reducing the cost of andfacilitating installation, maintenance, and periodic inspection of thesystem. The improved organization of work during construction of aplant, afforded by service centers of this invention, furthercontributes to erection economy. In this connection, the service centersmay be installed as complete factory built and tested units, resultingin improvement of job scheduling to a point near completion ofconstruction of a plant. Thus, it can be seen that a service centerconstructed in accordance with this invention completely fullls theobjectives of the invention as well as affording numerous otheradvantages.

While the invention has been described in terms of a preferredembodiment, it will, of course, be apparent that various modificationsand alterations could be made in the specific structure shown withoutdeparting from the invention. Accordingly, the foregoing description andaccompanying drawings are not to be taken in any way as limiting theinvention. Rather, the invention is to be limited only by the appendedclaims, which shall include within their scope all structure whichlogically falls within the language of these claims.

y I claim:

l. A casing fortan integrated operating air supply and air signaltransmission service center comprising: a flat rectangular upstandingrear wall having a pair of forwardly extending ilanges along vthe sidesthereof, a flat rectangular top wall extendingrhorizontal from the topwardly from the front of the flange and terminating vthe rear edges ofsaid side walls are received between said side flanges on the rear walland the side portions of the ange on said bottom wall and wherein thetop portions of said front and side walls are received within saiddepending flange on said top wall, the cover mounting means comprising afixed pin extending at right angles from each of said side portions ofthe flange on the bottom wall and disposed adjacent the front edge ofsaid bottom wall, each of said side walls being pro-vided with aJ-shaped slot disposed adjacent the bottom thereof and said first walland slidably receiving the pin on the adjacent side portion of thebottom wall ange with said pin residing in the shorter leg of saidJshaped slot in both said open and said closed position.

2. A casing for an integrated operating air supply and air signaltransmission service center and the like cornprising: a flat rectangularopstanding rear wall having a pair of forwardly extending tlanges alongthe side edges thereof, a at rectangular top Wall extending horizontallyfrom the top edge of said rear wall and having a depending ange alongthe front and side edges thereof, said depending flange forming acontinuation of the side anges on the rear wall, a flat rectangularbottom wall extending horizontally from the bottom of said rear wall andhaving an upstanding flange along its front and side edges with the sideportions of the ilange extending rearwardly from the front of the flangeand terminating closely adjacent said rear Wall, said side portions ofthe flange on the bottom wall being spaced in- 5 wardly of the casingfrom said side flanges on the rear wall, a U-shaped cover for the casingincluding a at rectangular front wall and a pair of side walls extendingrearwardly from the side edges of the front wall, and means mounting thecover for movement through approximately between an open position and aclosed position in which the rear edges of said side walls are receivedbetween said side flanges on the rear wall and the side portions of theflange on said bottom wall and in which the top portions of said frontand side walls are received within said depending flange on said topwall, the lower edges of said cover being disposed below and outside theupper edges of said upstanding ange on the bottom wall when the cover isclosed, the cover mounting means comprising a ixed pin extending atright angles from each of said side portions of the flange on thebottorn wall and disposed adjacent the front edge of said bottom wall,each of said side walls being provided with a J-shaped slot disposedadjacent the bottom thereof and said irst wall slidably receiving thepin on the adjacent side portion of the bottom Wall ange, the shorterleg of each of said slots being disposed closely adjacent the front edgeof said bottom wall and the larger leg of each of said slots beingdisposed between the shorter leg and said rear wall with said pinresiding in said shorter leg when said cover is in both said open Y andsaid closed position.

References Cited in the tile of this patent UNITED STATES PATENTS

1. A CASING FOR AN INTEGRATED OPERATING AIR SUPPLY AND AIR SIGNALTRANSMISSION SERVICE CENTER COMPRISING: A FLAT RECTANGULAR UPSTANDINGREAR WALL HAVING A PAIR OF FORWARDLY EXTENDING FLANGES ALONG THE SIDESTHEREOF, A FALT RECTANGULAR TOP WALL EXTENDING HORIZONTAL FROM THE TOPOF SAID REAR WALL AND HAVING A DEPENDING FLANGE ALONG THE FRONT ANDSIDES THEREOF FORMING A CONTINUATION OF THE SIDE FLANGES ON THE REARWALL, A FLAT RECTANGULAR BOTTOM WALL EXTENDING HORIZONTALLY FROM THEBOTTOM OF SAID REAR WALL AND HAVING AN UPSTANDING FLANGE ALONG ITS FRONTAND SIDE EDGES WITH THE SIDE PORTIONS OF THE FLANGE EXTENDING REARWARDLYFROM THE FRONT OF THE FLANGE AND TERMINATING CLOSELY ADJACENT SAID REARWALL, SAID SIDE PORTIONS OF THE FLANGE ON THE BOTTOM WALL BEING SPACEDINWARDLY OF THE CASING FROM SAID SIDE FLANGES ON THE REAR WALL, AU-SHAPED COVER FOR THE CASING INCLUDING A RECTANGULAR FRONT WALL AND APAIR OF SIDE WALLS EXTENDING REARWARDLY FROM THE SIDE EDGES OF THE FRONTWALL, AND MEANS MOUNTING THE COVER FOR MOVEMENT THROUGH APPROXIMATELY180* BETWEEN AN OPEN POSITION AND A CLOSED POSITION WHEREIN THE REAREDGES OF SAID SIDE WALLS ARE RECEIVED BETWEEN SAID SIDE FLANGES ON THEREAR WALL AND THE SIDE PORTIONS OF THE FLANGE ON SAID BOTTOM WALL ANDWHEREIN THE TOP PORTIONS OF SAID FRONT AND SIDE WALLS ARE RECEIVEDWITHIN SAID DEPENDING FLANGE ON SAID TOP WALL, THE COVER MOUNTING MEANSCOMPRISING A FIXED PIN EXTENDING AT RIGHT ANGLES FROM EACH OF SAID SIDEPORTIONS OF THE FLANGE ON THE BOTTOM WALL AND DISPOSED ADJACENT THEFRONT EDGE OF SAID BOTTOM WALL, EACH OF SAID SIDE WALLS BEING PROVIDEDWITH A J-SHAPED SLOT DISPOSED ADJACENT THE BOTTOM THEREOF AND SAID FIRSTWALL AND SLIDABLY RECEIVING THE PIN ON THE ADJACENT SIDE PORTION OF THEBOTTOM WALL FLANGE WITH SAID PIN RESIDING IN THE SHORTER LEG OF SAIDJ-SHAPED SLOT IN BOTH SAID OPEN AND SAID CLOSED POSITION.